Manufactured in 2002, the Jeep Liberty has always integrated the second phase of on-board diagnostics (OBD II). This newer vehicle diagnostic system standardized the placement of the data link connector (DLC) and the diagnostic trouble codes (DTCs). This simplified the process of diagnosing faulty sensors or modules in the vehicle that communicate to the vehicle's computer system. When a faulty DTC is detected in the Jeep Liberty's computerized system, it will trigger the "Check Engine Light" (also known as the malfunction indicator light or MIL), indicating an engine code has occurred.
Open the driver's side door of the Jeep Liberty and locate the diagnostic link connector (DLC) under the dash. It is located to the right of the steering wheel on the Liberty.
Plug the pocket scanner into the DLC and then turn the ignition key to the accessory position. This will power up all the electrical controls without the engine running. The scanner will get its power from the battery in the Liberty and will not require being turned on.
Read the onscreen menu of the scanner. While there are many makes and designs of pocket scanners, they are generally fairly universal in terms of operation. Most will feature a few options on the menu that you can scroll between and press an enter key to activate the function. If you're having trouble operating yours, refer to the owner's manual.
Choose "Erase" as an option. On some models, there may even be an "Erase" key. Simply press the key if that is the case on your pocket scanner.
Wait until the onscreen menu has displayed "Command Sent" or has defaulted back to the main menu.
Start the engine to the Liberty to determine if the "Check Engine Light" is out. If so, the engine codes are cleared. If not, further diagnosis is required.
